1. Field of the Invention
The field of the present invention is systems for lubricating a transmission for a motorized vehicle such as an automobile, or a motorcycle and particularly, improvements of such systems in which a lubricating oil is stored in a bottom of a transmission case containing the transmission, with gears of the transmission being partially immersed in the lubricating oil, so that the lubricating oil is scattered by rotation of the gears, thereby lubricating various portions of the transmission by a resulting oil splash.
2. Description of the Prior Art
In such a conventional transmission lubricating system, a specified amount of a lubricating oil is stored in the transmission case and, therefore, the oil level within the transmission case is always constant irrespective of the operational condition of the transmission.
In the above conventional transmission lubricating system, if the oil level within the transmission is set relatively high in order to supply a sufficient oil splash to various portions of the transmission during low speed operation of the vehicle, the lubricating oil may be stirred or violently agitated by the rotating gears during high speed operation, not only resulting in an increase in attendant power loss, but also bringing about a rise in the oil temperature. Conversely, if the oil level is set relatively low, in order to avoid unecessary stiring and agitation while still supplying a sufficient oil splash during high speed operation, then a sufficient splash is not provided during low speed operation, resulting in underlubrication. Therefore, it is difficult to effect the lubrication of the gears to a sufficient extent at all times over a full operating range of the vehicle, i.e., from the lowest speed to the highest speed. The higher the maximum vehicle speed, the more problematic this becomes.